SAFETY AND COMPATIBILITY OF BETAXOLOL HYDROCHLORIDE COMBINED WITH DILTIAZEM OR NIFEDIPINE THERAPY IN STABLE ANGINA-PECTORIS

Compared with-placebo, adding betaxolol 20 mg every day to nifedipine (up to 60 mg/day in divided doses) or diltiazem (up to 360 mg/day in d ivided doses) for a 3-week treatment period in 135 patients with stabl e angina pectoris significantly (p <0.05) lengthened the time to onset of moderate angina during exercise tolerance tests at all treatment t ime points. The median increases in the time to onset of moderate angi na at the final exercise tolerance test (end point) compared with base line were 1.08 and 0.53 minutes for betaxolol and placebo groups, resp ectively (p = 0.002, betaxolol vs placebo). The time to onset of 1 mm ST-segment depression increased significantly (p <0.05) with betaxolol compared with placebo at all but 1 treatment time point (median incre ase [p = 0.001] 1.77 and 0.37 minutes, respectively, at end point). Du ration of exercise also was increased significantly (p <0.05) after th e third week of treatment and at end point (median 0.62 and 0.50 minut es, respectively; p =0.03). Generally comparable results were found wi thin the diltiazem (n = 128) and nifedipine (n = 25) subgroups, althou gh the nifedipine group was too small to detect statistically signific ant differences between betaxolol and placebo treatment. nesting systo lic blood pressure, heart rate and the rate-pressure product, measured both when angina occurred and at the end of exercise; also were influ enced significantly (p <0.05) by the betaxolol addition. The only seri ous adverse effect associated with betaxolol treatment was syncope, se en in 2 patients.